The US Center for Disease Control and Prevention (CDC) reports that ˜1.7 million people sustain traumatic brain injury (TBI) each year. With the increased knowledge of the possible serious and long lasting ramifications of TBI, a great deal of research has become focused on developing improved protective gear and procedures to help protect against the injuries induced by TBI and mild-TBI, especially in sports and military applications. Due to the limitation of in-vivo strain measurement in human brain, other kinematic parameters of head, such as head linear acceleration (to define linear impact of head contact) and angular acceleration (to define inertial loading of head), are used for study of brain injury mechanisms. Several systems incorporating microelectromechanical systems (MEMS) inertial sensors into helmets have been developed and employed, with the Head Impact Telemetry System (HITS) being one of the earliest and most widely used.
The primary disadvantage of using sensors that are incorporated into a helmet is that the sensors in the helmet may not accurately measure the acceleration forces being delivered to the head of the user. In particular, the head acceleration induced by an impact could be different from the helmet acceleration depending on variations caused by different fit tightness and wear conditions between the head of the user and the helmet. For more precise measurements of head accelerations, it is necessary to have any sensors coupled more directly to the head of a user to eliminate the inaccuracies caused by the fit of a helmet and the helmet movements that are independent of the head of the user. While certain head acceleration sensors in the form of earplugs have been developed, those sensors require a hard wired connection to the data recording portion of the system.
Therefore, there is a need in the art for a system and method for wirelessly measuring and recording head acceleration caused by impacts in helmeted activities through the use of a reduced number sensors that are tightly coupled to the head of a user. These and other features and advantages of the present invention will be explained and will become obvious to one skilled in the art through the summary of the invention that follows.